Riveting-machine.



PATBNTBD JAN. 13,1903. G. E. MARTIN.

RIVETING MACHINE.

APPLICATION FILED DEG. 21, 1901.

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PATENTBD JAN. 13, 1903. G. E. MARTIN.

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pm. mwwirzlw RIVETING MACHINE, I APPLICATION FILED DBO. 21, 1901.

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1' z nRnsPEfERscn HOTO- 'r 0 W5 GTO 0c NITED TATES ATENT FFICE.

GEORGE E. MARTIN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE PEDRIOKdo AYER COMPANY, OF PHILADELPHIA, PENNSYLVANIA.

.RIVETING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 718,365, dated January13, 1903. Application filed December 21,1901. Serial No. 86,734. (Nomodel.)

To all whom it may concern:

Be it known that I, GEORGE E. MARTIN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inRiveting- Machines, of which the following is a specification, referencebeing had therein to the accompanying drawings.

This invention relates to pneumatic riveting-machines in which the forcethat operates the riveting devices is transmitted from thepower-cylinder through a liquid medium.

In order that. the invention may be readily understood, I will firstdescribe the operation of the same and refer incidentally to the partsand detailed construction of the machine illustrated in the accompanyingdrawings, and subsequently will point out in the appended claims thenovel characteristics of the invention.

In Figures 1 and 2 the machine is shown in side elevation, partly insection,with the principal elements composing the operative parts inrelative position, respectively, at the commencement and termination ofoperation.

' Fig. 3 is an exterior, side view of the powercylinder detached fromthe frame by'broken lines and showing the operating-lever of the airadmission and exhaust valve, and the passages and pipes communicatingtherewith shown partly in dotted lines. Fig. 4 is'a front elevation,partly in section, of the cylinder containing the dolly-bar and pistonand a connected auxiliary cylinder containing a floating piston. Fig. 5is a plan view of the base of the frame with the power-cylinder detachedand showing the relative position of the cylinders 0 0 Fig. 4. Fig. 6represents an enlarged view, partlyin section,of a relief-valve thatcontrols a passage leading from the dashpot provided at the forwardend'of the powercylinder. Fig. 7 is an enlarged end View, partly insection, of the bonnet or cover of the power-cylinder containing theair-admission valve and connected ports and passages; and Fig. 8 is anenlarged central longitudinal section of the power cylinder and pistonand airadmission valve. Fig. 9 is an enlarged sectional elevation of thecylinder containing the dolly bar and piston with communicating portsand passages, the relative position of the parts indicating thepreliminary contact of the riveting-tools with the rivet.

Referring to Fig. 1 of the drawings, the parts are shown relatively instarting position, air

under compression being admitted to the valve-chamber 1 through theinlet-pipe w, the valve 2 being ,set to allow the air to pass throughthe open port 3 into passages 4 and 5 and annular space a and act uponthe piston P and force it to the inner end of the cylinder C. At thesame time the air is also admitted through the pipe 6 into the annularspace 8 in the cylinder 0 of the dolly-bar R, thereby forcing thedolly-bar piston -P to its extreme open throw. The air-admission valve 2is now moved by the operating-handleHindirection to register the port 3with the exhaustport 13 to permit theair-pressure to escape from theannular space aim the power-cylinder and from the annular space 8 in thedolly-bar cylinder 0 In this movement of the valve 2 the port 14 isfirst opened and the air under light pressure is admitted to passages17, 18, 19, and 20, Figs. 3 and 7, and through pipe 21'and passages 22,and 23, Fig. 1, into the space 15 of the auxiliary cylinder C ,'Fig. 4.The piston 16 in the auxiliary cylinder C is moved forwardunder thislight pressure, and the liquid in the cylinder 0 is forced through theport 24, Fig. 4, and passages 25, Fig. 9, and past the check-valve 26into and filling the chambers 27 and 28, Figs. 8 and 9, and moving thedolly-bar piston P to the position shown in Fig. 9, which brings thedolly-rod R and riveting-die 'D in contact with the shank of the rivet12, as shown. During this primary movement of the dolly-bar theairpressure is excluded from thepower-piston P. Upon a further movementof the air-admission valve 2 port 30, Fig. 1, is opened and pressureadmitted through passage3l to the piston P in the power-cylinder, whichupon starting intensifies the liquid-pressure in the chambers 27 and 28by the displacement of the hollow fixed spindle P in the chamber '28 andcloses the check-valve 26, Fig. 2. The

continued movement of the power-piston upon the hollow fixed spindle Pforces the liquid in chamber 28 through the spindle, producing anintensified pressure in the chamber 27 by the increasing displacement ofthe spindle P in chamber 28, which acts upon the piston P and forces thedolly-bar R and riveting-die D to act upon and form the rivet-head undergreat and increasing pressure, as shown in Fig. 2. In the returnmovement of the piston P and to insure its complete movement by therelief of all the liquid contained in the chambers 27 and 28 the stem ofthe check-valve 26 is connected with a small piston 34, fitted within arecess made in the end plug 35 of the dolly-bar cylinder. (See Fig. 9.)Upon the return of the parts, as shown in Figs. 1 and 4, wherein theair-pressure is admitted to the annular space 8, it is also admittedthrough the passages 36, 37, and 3S, beneath the piston 34, Fig. 9,which forces the check-valve 26 to open and permit the superfluousliquid in the chamber 27 to return through the passages 25 and 24, Figs.9 and 4, to the auxiliary cylinder 0 This auxiliary cylinder C isprovided with a plug 39 for purpose of refilling the same.

In the head of the power-cylinder a chamber or recess 40 is provided toact in connection with the projecting part 41 of the powerpiston forchecking the return movement of the piston near the termination of thestroke, a relief-valve 42 (shown in the enlarged and detached view, Fig.6, and end view, Fig. 7) being provided to permit the power-piston tofully complete its return stroke and to admit a small amount of air inthe chamber or recess during the beginning of the forward stroke of thepower-piston P. This device is well known in this class of machines andis not claimed herein.

The power-piston is constructed with an annular ring P and hollow trunkT of less diameter than the power-cylinder, which provides for thesurrounding annular space a, and the correspondingly-d1minishedefiective piston area exposed to the operating pressure during itsreturn movement, whereby an economy is obtained in the less quantity ofair used. This hollow trunk portion T has an interior chamber 28 forholding the liquidtransmitting medium and is provided at its head 32with an opening and stuffing-box 33, by which the trunk T moves upon thefixed hollow spindle P.

In Figs. 1 and 2 the machine is shown in an inverted position withrespect to the Work to be performed for convenient use in particularplaces and in order to place the rivet through the plates from above andprevent it from dropping out before the riveting-die is brought incontact. The machine, however, may be suspended by either of therespective bails shown and employed in the reverse position whendesired.

What I claim, and desire to secure by Letters Patent, is-

1.. In a riveting-machine, the combination of a power-cylinder providedwith a diiferential power-piston constructed with a hollow trunk forcontaining a liquid, a fixed hollow spindle communicating therewith andwith the riveting piston-cylinder; a minor pistoncylinder communicatingindependently with the air-pressure and with the riveting-cylinder, anda check-valve device with means for operating the same located betweenthe riveting and the minor cylinder, for the purpose set forth.

2. In a riveting-machine substantially as described, the combination ofa riveting piston-cylinder C and a minor cylinder and piston C with thecheck-valve 26, connected piston 34, and communicating passages 36, 37,38, whereby said check-valve 26 is opened upon the admission of theoperating air-pressure to the valve-piston 34 to permit the containedliquid in the chamber 27 to pass to the minor cylinder C throughpassages 24, 25, for the purpose set forth.

In testimony whereof I at'fix my signature in presence of two witnesses.

GEORGE E. MARTIN.

Witnesses:

J. HARRY 000K, GEORGE GEOFF.

